Uh, sure you can. I would recommend getting the K&B 1.5 book, sure. But it is certainly possible to take the exam and do well on it without that book, or any book for that matter. It's just harder.
cmon Jim it's an unwritten rule i guess, you should read kathy and Berts book to do well. people ofcourse can do well by reading JSR's but someone who has SCJP 1.4 book and wants to give 1.5 exam based on that would never succeed and i guess that's what he asked.